In the centre of the mastoid process, at the junction of the middle and lower third of the curve formed by Yifeng (SJ-17) and Jiaosun (SJ-20) posterior to the helix.
Posterior to the ear, in a small depression on the mastoid bone, one third of the distance along a curved line drawn from Yifeng SJ-17 to Jiaosun SJ-20 following the line of the rim of the ear.
Needling Method:
Puncture subcutaneously 0.3-0.5 inch or prick with a three-edged needle to cause bleeding. Moxibustion is applicable.
References
Acupuncture
11.Grasping the Wind(First Edition) - Andrew Ellis, Nigel Wiseman, Ken Boss